Ammonium hydroxide polymer solutions for floor polish compositions

ABSTRACT

AQUEOUS SOLUTIONS OF AMMONIUM SALTS OF A SMALL GROUP OF HALF ESTERS FORMED FROM MALEIC ANHYDRIDE-OLEFIN COPOLYMERS ARE USEFUL IN IMPROVED FLOOR POLISH FORMULATIONS. THE CLASS OF COPOLYMERS INCLUDE PARTIALLY ESTERIFIED COPOLYMERS OF MALEIC ANHYDRIDE WITH 1-HEXENE, 1-BUTENE DIMERS, 1-OCTENE AND 1-DECENE IN OLEFIN/MALEIC ANHYDRIDE MOLAR RATIOS OF 1 TO 1.5, HAVING ACID NUMBERS OF AT LEAST 150, NO ANHYDRIDE GROUPS OR ADJACENT CARBOXY GROUPS AND INHERENT VISCOSITIES IN ACETONE AT 25*C. OF FROM ABOUT 0,04 TO 1.1 DECILITERS PER GRAM AT 5 G./DL. CONCENTRATION.

United States Patent Olfice 3,598,778 Patented Aug. 10, 1971 3,598,778 AMMONIUM HYDROXIDE POLYMER SOLUTIONS FOR FLOOR POLISH COMPOSITIONS Donald L. Burdick, Overland Park, Kans., and William J.

Heilman, Allison Park, and Gerald J. Mantel], Allentown, Pa., assiguors to Gulf Research & Development Company, Pittsburgh, Pa.

No Drawing. Original application Jan. 19, 1967, Ser. No. 610,253, now Patent No. 3,488,311. Divided and this application Mar. 19, 1969, Ser. No. 816,476

Int. Cl. C08f 27/12, 43/08; C09g 1/10 US. Cl. 26029.6H 4 Claims ABSTRACT OF THE DISCLOSURE DESCRIPTION OF THE INVENTION This is a division of US. patent application Ser. No. 610,253, filed Jan. 19, 1967, now US. Pat. 3,488,311.

In the manufacture of floor polish of the aqueous dispersion type, it is now common practice to include in polish formulations an aqueous solution of an ammonium salt of a carboxy-substituted polymeric product derived from a copolymer of styrene and maleic anhydride. Soluble resins of this type are often referred to as leveling resins. The polishes made with the use of polymer solutions of this type show improved heelmarkresistance, lighter color and better thermal stability than the prior art polish formulations. However, they are somewhat deficient in many formulations, particularly with respect to recoatability and waterspot resistance. These defects appear to be associated with poor compatibility with some of the other ingredients in polish formulations.

A class of soluble resins has now been discovered which are more compatible with the ingredients of polish formulations and confer on these aqueous dispersion polishes better coatability, recoatability, gloss, jetness, transparency, leveling and resistance to waterspotting, while maintaining the good heelmark-resistance, light color and thermal stability of the modified styrene-maleic anhydride copolymers.

Briefly, the new ammonium hydroxide soluble resins are partially esterified copolymers of maleic anhydride with an olefin selected from the group consisting of l-hexene, l-butene dimers, l-octene and l-decene in olefin/maleic anhydride molar ratios of from about 1 to 1.5, which have acid numbers of at least 150, are substantially free from anhydride structures and adjacent free carboxy groups, at least half of the carbonyl groups being present in the form of esters of primary alcohols having from one to four carbon atoms, the inherent viscosity of the copolymers measured at 77 F. (25 C.) in acetone being within the range of about 0.04 to 1.1 deciliters per gram (at 5 g./dl. conc.). An especially preferred resin is the partially esterified approximately equimolar copolymer of l-hexene with maleic anhydride in which about half of the available carboxy groups are present in the form of the methyl ester. This resin, in addition to other advantages over the styrene-maleic acid copolymers, can be dissolved in aqueous ammonium hydroxide at room temperature, without heating, to yield solutions of relatively high solids content at low viscosity.

The improved floor polish compositions which employ the new resins comprise an aqueous solution of the ammonium salt of a partially esterified copolymer of maleic anhydride with an olefin selected from the group consisting of l-hexene, l-butene dimers, l-octene and l-decene having an olefin/maleic anhydride molar ratio from about 1 to 1.5, which have acid numbers of at least 150, are substantially free from anhydride structures and adjacent free carboxy groups, about half of the carbonyl groups being present in the form of esters of primary alcohols having from one to four carbon atoms, the inherent viscosity of the copolymer being within the range of about 0.04 to 1.1 dl./g., at least one other resin or a wax in aqueous dispersion, and at least one organic solvent.

Suitable resins for manufacture of the improved polish compositions may be made as described below.

Maleic anhydride will copolymerize readily with l-olefins, including l-hexene, l-olefins made by dimerization of l-butene and various 8 to 10-carbon l-olefins. The process generally consists of polymerization in solution in a convenient solvent such as benzene at a temperature between about 60 and 100 C., initiated with a free radical initiator as, for example, about 2 to 3 Weight percent of benzoyl peroxide based on maleic anhydride. An excess of l-olefin, preferably in a molar ratio of about 2:1 is customarily employed in order to increase the conversion of maleic anhydride to copolymer. The molecular weight may be reduced as desired by use of chlorinated hydrocarbon chain-transfer agents such as carbon tetrachloride. The following procedure is given for illustrative purposes.

l-hexene and maleic anhydride are conveniently copolymerized in solution in propylene dichloride. The polymer is formed either in solution or in a second liquid phase, depending upon the amount of solvent and monomer present. l-hexene acts as a non-solvent for the polymer, and as the ratio of hexene to propylene chloride is increased, the polymer forms in a separate liquid phase, as indicated in the table below. In a typical polymerization the volume of propylene dichloride may be kept at twice the volume of hexene and the reaction system will remain a single liquid phase. The polymer is then conveniently recovered by precipitation upon the addition of an aliphatic hydrocarbon such as heptane. When about two volumes of heptane per volume of propylene dichloride are mixed with the product solution at room temperature, a fine, easily filterable polymer powder is precipitated in suspended form. Unreacted maleic anhydride can be removed by leaching with boiling heptane or octane. If the reaction is carried out at about C. for 12 to 14 hours with at least .01 mole of benzoyl peroxide per mole of maleic anhydride, essentially all of the maleic anhydride is reacted, so that leaching of unreacted maleic anhydride from the product is unnecessary. The polymer, after filtering, may be dried under vacuum to remove residual hydrocarbons. The solvents employed and the un- Ieacted l-hexene are normally separated by distillation and recycled to the process.

TABLE I.COPOLYMERIZATION OF l-HEXENE WITH MALEIC ANHYDRIDE [Char-go: 1,000 cc. propylene dichloride; 196 g. to 784 g. maleic anhydride (28 moles): 4.84 g. bcnzoyl peroxide (0.02 mole)] Following the procedure outlined above employing a mole ratio of reagents of about 4 moles of hexene to 2 moles of maleic anhydride with .02 mole of benzoyl peroxide, essentially complete conversion of maleic anhydride to a copolymer containing approximately equimolar proportions of olefin and maleic anhydride is obtained at about 80 C. within ten to twelve hours. The polymer product recovered by filtration is then esterified by reacting with alcohols such as methanol, ethanol, propanol or butanol.

The catalyst for this reaction can be any material having an ionization constant at 25 C. of at least about 1 10- Suitable catalysts include liquid mineral acids having the required ionization constants, for example, sulfuric, hydrochloric, nitric and phosphoric acids; organic acids, such as benzene sulfonic and p-toluene sulfonic acids which are readily soluble in the reaction medium; and solid acidic materials including, but not limited to ion exchange resins. The mineral acids normally come in aqueous solution and concentrations in aqueous solution between 25 percent and 100 percent are suitable. Concentrations of acid below about 25 percent are especially unsuitable when the higher carbon number (above 4) alcohols are employed since the more dilute acid will cause formation of a separate aqueous phase in the reactor.

The amount of liquid acid catalyst employed can vary over a wide range. Usually the weight percent of anhydrous acid based on the weight of copolymer is between 0.05 and 5, preferably between 0.1 and 1 weight percent.

The esterification reaction occurs by contacting the anhydride and alcohol charge stocks at a temperature and for a time sufficient to result in the formation of the halfester. The reaction temperature is suitably between 40 and 180 C. The initial reaction temperature can be an elevated temperature of between, for example, 100 to 120 C., but at least the final portion of the reaction must be run at a temperature below about 80 C. for a time sufticient to convert substantially all of the anhydride groups to half-ester groups. It has been discovered that, in order to obtain a substantially pure half-ester compound, i.e., free of cyclic anhydride groups, from the reaction of the copolymer anhydride with an alcohol, the reaction temperature during at least the final portion of the esterification reaction, and the temperature during the recovery of the half-ester must be maintained below about 80 C. At temperatures above about 80 C., the half-ester compounds formed in accordance with this invention tend to decomposed, yielding cyclic anhydride structures and alcohol, especially under conditions such as may exist in a drying oven, where the alcohol is removed as it is formed. In order to obtain a faster rate of reaction initially, it is feasible to employ a reaction temperature between 80 C. and 180 C., usually between 100 C. and 120 C., so long as the final portion of the esterification reaction is run at a temperature less than about 80 C., and sufiicient alcohol is maintained in contact with the anhydride compound to assure formation of the halfester. The half-ester is theexclusive initial reaction product and no diester forms unless and until water is removed from the reaction zone, even in the presence of an excess of a water soluble alcohol, such as methanol.

The reaction pressure is not critical, but should be such that the reactants and products are maintained in the liquid phase. Suitable reaction pressures include atmospheric to 100 p.s.i.g. or higher.

The preferred alpha olefin-maleic anhydride copolymers are initially insoluble in the alcohol and gradually dissolve in the alcohol as the half-ester is produced. Sufficient alcohol is normally employed to not only serve as a reactant, but to serve as a solvent for the system. As a practical matter, the volume ratio of alcohol to the anhydride form of the copolymer is usually between 20:1 and 100:1, which assures formation of a product solution with a viscosity low enough to make the solution easy to handle, i.e. to pump or stir.

If desired, stoichiometric amounts of alcohol can be employed together with a mutual solvent for the reactants. Suitable mutual solvents include benzene, acetone, 2- butanone, propylene chloride, and iso-octane. However, the use of a mutual solvent involves added expense and diificulties in the separation of products.

The reaction time should be suflicient to result in the formation of the desired half-ester. The usual reaction time is between 0.5 and 24 hours. The exact reaction time can be determined by following the reaction with suitable means, such as with infrared analysis until the anhydride carbonyl absorption peak disappears, that is, by periodically removing samples and subjecting them to analysis, such as infrared, to determine if any carbonyl groups are present as anhydride groups. This time can be shortened by the initial use of high temperatures, but the completion of the reaction, usually the last 20 to 60 minutes, must be at a temperature below C., usually between 40 and 60 C.

The reaction can be run in a batch or continuous manner or through a coil type reactor.

The reaction products are recovered by any suitable procedure. If it is desirable to recover the half-ester substantially free of anhydride, the temperature during the recovery procedure must at all times be maintained below about 80 C., preferably between 0 C. and 60 C. Half-esters prepared by using alcohols having between 1 and 4 carbon atoms can be recovered in a solid particulate form by precipitating the half-ester from reaction solution by contact with an excess of water at a temperature below 80 C., preferably room temperature. The half-esters are recovered by filtration, are washed with water to remove any traces of alcohol and acid catalyst and are then dried under a vacuum, (preferably a pressure of between 1 and 50 mm. of Hg) at a temperature suitable to obtain the product desired. To obtain a product substantially anhydride free, temperatures less than 80 C., preferably between 0 and 60 C. should be employed. An inert dry gas, such as nitrogen, can be passed over the solid half-ester to aid in the drying process. By dry is meant substantially free, i.e., less than 2 weight percent, of physically bound alcohol. The particulate solid half-ester obtained by this procedure is pure white in color. A Itayrliical half-ester preparation is specifically exemplified e ow.

In this example, 237.4 grams of equimolar l-hexenemaleic anhydride copolymer and 662.4 milliliters of methanol were employed along with 2.37 grams of percent phosphoric acid. The Weight percent of anhydrous acid based on the copolymer was 0.85. The react1on was run for 10.5 hours at 64 C. Nine samples were taken over the course of the reaction and subjected to infrared analysis to determine the anhydride carbonyl content of the reaction mixture. The reaction was terminated when the ninth sample indicated the absence of anhydride carbonyl absorption peaks. A yield of 262.1 grams of dried polymer was obtained. The polymer had a dilute solution viscosity in acetone of 0.078 deciliter per gram, and an acid number of 256. The theoretical acid Copolymer properties, Ester properties flinh Comonomer d1./g. Alcohol Acid No.

l-hex'e'ne 0. 80 n-Butyl 196 D 0. 80 Isobutyl 187 0. 68 PropyL. 1 0. 06-0. 07 Methy 236-254 0. 07 Propyl. 212 0. 06 .-...do-- 225 0. 08 Methyl.-. 204 l-hexene 0. 10 n-B utyl 186 Norr:.-Inherent viscosities measured in acetone at 77 F. and a concentration of g. per deciliter.

Several characteristics of the esterified polymers can be controlled so as to render them soluble in aqueous basic media and suitable for use in polish formulations. These are discussed individually below.

Influence of alcohol chain length With increasing length of the alcohol carbon chain there is decreasing solubility in aqueous ammonia, increasing viscosity in solution, slight decrease in compatibility with other polish ingredients and some decrease in performance evaluation of polishes. Primary alcohols of one to four carbon atoms are found to give the best performance in polish formulations.

Influence of acid number With increasing acid number the solubility in aqueous ammonia increases and there is an increasing tendency of polish films to be water-sensitive. Acid number should be sufficiently high to assure solubility (about 150) but no higher than the theoretical value for 50 percent ester for consistently good performance. In products which have been esterified beyond the 50 percent level, there are present some adjacent carbalkoxy structures. These have a tendency to reduce solubility, particularly in higher molecular weight copolymers and when the esters are propyl or butyl. If consistently good solubility in aqueous ammonia is desired, it is best to terminate esterification when the acid number of the product is approaching the theoretical value for the half ester. In the preferred products the distribution of carboxy and carbalkoxy groups in the copolymer molecules appears to be random, as indicated by conventional chemical and physical tests.

Influence of molecular weight With increasing molecular weight of the esterified copolymers, polish performance is better with respect to durability and other properties. For satisfactory performance, the molecular weight should be sufiiciently low to assure solubility and a solution viscosity which is low enough for convenient use in formulating polishes. The inherent viscosity of the copolymer should be from about 0.04 to 1.1, preferably from 0.05 to 0.5, with an acid number approaching the theoretical value of the halfester, preferably about 185 to 250 for best all-around performance in a variety of polish formulations. For out standing ease of formulation, the products of lower inherent viscosity and higher acid number are more desirable. Such products dissolve more readily, form less viscous solutions, are very compatible with other polish ingredients and are very consistent in giving good performance. The use of a versatile product of the latter type is specifically exemplified below.

There was dissolved in aqueous ammonium hydroxide a methyl ester of a copolymer of hexene and maleic anhydride prepared according to the procedure described above, yielding a solution of workable viscosity at 20 percent solids content. The methyl ester copolymer had a softening point of approximately 131 C., an acid number of 250, an inherent viscosity of 0.06 and was obtained by esterification of an approximately equimolar copolymer of l-hexene with maleic anhydride. Three polish formulations were prepared having a 15 percent solids content and employing the copolymer ester solution. The compositions of the three formulations are indicated in the following table:

TABLE II.15% SOLIDS POLISH DISPERSIONS Formula I II III Parts Aqueous resin dispersions:

Modified polystyrene latex (Ubatol UL-2001) at 0 m giii'eii'iyiii'r'yiiiii'(i redcfiili iiiif' 0. Modified acryliclatex(RhoplexB-23l)at15% 72.5 Aqueous polyethylene dispersion (Poly-Em) at 15% 20.0 15.0 11.0 Hexene-maleic copolymer methyl ester solution at 15% 20.0 15.0 16.0 Organic solvents:

Tributoxy ethyl phosphate 0.8 0.5 0. 4 Carbitol 0.1 2.0 1 25 Ethylene glycol.-- Dibutyl phthalate Butyl benzyl phthalateu Oleic acid Surface active leveling agen factant (EC-128) at 1% 1.0 1. 0

The polish formulations were evaluated on vinyl asbestos floor tiles by A.S.T.M. procedures or modifications thereof recommended by the Chemical Specialties Manufacturers Association. The results appear in the table below.

TABLE TIL-EVALUATION OF POLISH FORMULAS OF TABLE II Polish formulation I II III Gloss:

Single coat Very good Good Good.

Double coat. Excellent- Excellent- Excellent. Recoatability (1 hr Very good-.. do Do. Waterspotting 2 hrs Moderate. Slight. Moderate.

24 hr Slight to very ..do Moderate to slight. Leveling ood Good Good. Removability- Excellent. Excellent Excellent. Haze o No No. Heelmark resistance Good- Very good Excellent. Static coeflicient of friction 1 0.44 .35 0.51. Freeze-thaw stability:

Number of cycles" 3. 3... 3.

Initial pH 9.3 9.3 7.3.

Final pH 9.3-- 9.3 7.8

Haze- No Moderate to slight..- No. Oven stability (30 days):

Initial pH 9.3 9.3 7.8.

Final pH..-. 9.3 9.3-... 7.8.

Haze- Very slight Slight No.

1 Very good gloss and jetness. 2 GSA N o. 1 Control-0.36

Nora-Environmental conditions: Temperature, 72 F.; relative humidity, 47%.

A corresponding propyl ester was made by esterificttion of the copolymer of l-hexene and maleic anhydride. The propyl ester had a softening point of 106 C., an acid number of 212 and dissolved readily in aqueous ammonium hydroxide. The solution of the propyl ester in ammonium hydroxide was employed in three polish formulations corresponding to Formulas I, II and III above which were tested on vinyl asbestos floor tiles. The results obtained were substantially equivalent to those which appear in Table III. The only significant difference which appeared in the results was in heelmark resistance, which only rated good. This difference in behavior is probably attributable to the lower softening point of the propyl ester. The gloss, leveling, recoatability and water spotting resistance in all instances were consistently better when compared with the performance of a corresponding commercial ammonium hydroxide-soluble styrene-maleic acid resin.

In addition to the ammonium salts, the half-ester copolymers of the present invention also form water-soluble salts with various water-soluble amines such as morpholine or the ethanolamines. The aqueous solutions of amine salts are equally useful in formation of improved floor polishes. However the ammonium salts are preferred because rthey are cheap and quickly yield good polish coatings which are odorless, colorless, durable and yet are easily removed prior to recoating.

The half-ester copolymers of the present invention are suitable for use in heavy duty buffable polishes and in dry-bright polish formulations of the type which yield finishes which are resistant to detergents and are therefore washable, but which are readily removable with aqueous ammonia. The compositions of typical formulations are tabulated below, along with formulations employing a modified styrene-maleic anhydride copolymer, for purposes of comparison.

TABLE IV.-DETE R GENT-RESISTANT POLISH F RMULAIIONS Formula IVIggly fied polystyrene latex (Ubatol U-3101) at Hard wax emulsion (oxidized mierocrystalline- 2-pyrrolidone 0 5 0.5 Fluorinated anionic surfactant (FC-128) at 1% 1. 0 1. 0 1. 0 1. 0

Formulation 1 showed the best resistance to detergents, while being readily removable with detergents containing ammonia.

8 Formulations l-4 are detergent resistant polishes. These were tested for ability of the polish coating to resist three cleaning compositions. Results were as follows:

Formulation 5 was applied to vinyl asbestos tile and evaluated according to bench test procedures, as in Table III. Results are tabulated below.

TABLE VI Evaluation of Formulation No. 5

Gloss:

1 coat Fto G.

Buffed +(V.G.).

2 coats F to G.

Buffed +(V.G.).

Recoat V.G.

Drag None. Waterspotting:

2 hrs. S1.

24 hrs V. sl.

Leveling G.

Removability 40 strokes.

Haze S1. to V. S].

The performance of the novel copolymer half-esters was clearly satisfactory in this heavy buffable industrialtype polish formulation.

What is claimed is:

1. The partially esterified copolymer of maleic anhydride with an olefin selected from the group consisting of l-hexene, l-butene dimers, l-octene and l-decene in a molar ratio of olefin to maleic anhydride of from about 1 to 1.5, which has an acid number of at least 150, is substantially free from anhydride structures and adjacent free carboxy groups, at least half of the carbonyl groups being present in the form of esters of primary alcohols having from one to four carbon atoms, said copolymer having an inserent viscosity in the range from about 0.04 to 1.1 deciliters per gram, measured at a concentration of 5 g. per deciliter in acetone at 25 C.

2. The aqueous solution of an amine salt of a copolymer according to claim 1.

3. The aqueous solution of an ammonium salt of a copolymer according to claim 1.

4. The aqueous solution of the ammonium salt of a partially esterified, approximately equimolar copolymer of l-hexene with maleic anhydride according to claim 1 in which about half of the carbonyl groups are present in the form of the methyl ester.

TABLE V.-NUMBER OF STROKES TO REMOVE FINISH Formulation Cleaning composition 1 2 3 4 (1) 1.5% solution of laundry detergent (Tile) 200 (10%) 200 (4 (7 1 (2) Industrial soap solution with 0.5% NHiOH B6 44 88 (3) 1.5% solution of laundry detergent plus 2.8% NHiO 40 08 26 19 References Cited UNITED STATES PATENTS 3,034,876 5/1962 Gee et al 44-62 13,236,797 11/ 1966 Williams 260-29.6 3,461,108 18/1969 Heilman et al. 260-785 MELVIN GOLDSTEIN, Primary Examiner US. Cl. X.R.

1E6028.5AV, 78.5T, 897B, 901

*zg ggg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,598,778 Dated August 10, 1.97}

Inventor(s) Donald L. Burdick William J. Heilman, and Gerald J.

Mantell It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 64, the word "decomposed" should read decomposeto be correct.

Column 7, line 53, that portion of the formula reading "1.0 1.0 1.0 1.0" should read --l.0 1.0 1.0 1.0 1.0"--

to be correct.

Column 8, lines 1, 2, and 3, should be in Column 7, after the Table IV.Detergent-Resistant Polish Formulations, to be correct.

Column 7, Table V.Number of Strokes to Remove Finish should follow after the above 3 lines in order to be correct.

Column 7, lines 54, 55, and 56 should follow after the above Table V.Number of Strokes to Remove Finish, in order to be correct.

Column 7, in Table V.Number of Strokes to Remove Finish, line (1) the word, ('Ii e) should read (Tide) to be correct.

Column 8, line 44, the word "inserent", should read inherent to be correct.

Signed and sealed this 13th day of June 1972.

(SEAL) Attest:

EDWARRNLPLETCHERJR. ROBERT GOTTSCHALK '-\ttest1ng Officer Commissioner of Patents 

